Flat wall panel at least substantially made of cellulose material

ABSTRACT

A flat wall panel at least substantially made of cellulose material, a special feature being the fact that the wall panel is at least substantially made of layers of paper/cardboard, each layer at least substantially being made up of a corrugated sublayer and a flat sublayer provided on one side thereof, which layers of paper/cardboard are interconnected via an adhesive applied to the corrugations of the corrugated sublayers, wherein the wall panel is impregnated, in particular with a resinous material, and wherein at least one strengthening layer having a greater elasticity modulus than the layers of paper/cardboard is provided, which strengthening layer is connected to a layer of paper/cardboard on one side of the wall panel via an adhesive.

CLAIM OF PRIORITY

This application claims priority to the Netherlands Patent ApplicationNo. NL 1024505, entitled FLAT WALL PANEL AT LEAST SUBSTANTIALLY MADE OFCELLULOSE MATERIAL, by Snel, filed 10 Oct., 2003, incorporated herein byreference.

TECHICAL FIELD

The present invention relates to a flat wall panel at leastsubstantially made of cellulose material. The invention also relates toa method for manufacturing said wall panel.

BACKGROUND

Such a wall panel is known from German patent No. 2 026 768. Said patentdescribes a building that is built up of a great many differentconstruction elements, such as a concrete floor, roof and side wallpanels made of an intermediate layer of corrugated cardboard sandwichedbetween two flat outer layers, as well as cramps and corner elements. Inpractice, the constructional strength of the roof and side wall panelsappears to be insufficient to give the building sufficient strength.

SUMMARY

The object of the invention is to improve the wall panel that is knownfrom the aforesaid German patent publication, in the sense that a wallpanel having an optimum constructional stiffness is provided for use asa construction element of a building, as a wall panel in, for example, aseparation wall, etc. It is noted that the term wall panel is understoodto include an element for use in a wall, a floor, a ceiling, a roof,etc.

According to the invention, a wall panel of the kind referred to in theintroduction is characterized in that the wall panel is at leastsubstantially made of layers of paper/cardboard, each layer at leastsubstantially being made up of a corrugated sublayer and a flat sublayerprovided on one side thereof, which layers of paper/cardboard areinterconnected via an adhesive applied to the corrugations of thecorrugated sublayers, wherein the wall panel is impregnated, inparticular with a resinous material, and wherein at least onestrengthening layer having a greater elasticity modulus than the layersof paper/cardboard is provided, which strengthening layer is connectedto a layer of paper/cardboard on one side of the wall panel via anadhesive.

In other words, the sum of a number of adhered-together layers ofpaper/cardboard are connected on at least one flat (outer) side thereofto the less elastic strengthening layer. Experiments have shown that thepresent construction leads to an unexpectedly great constructionalstiffness of the wall panel, so that it is possible to subject the wallpanel to large forces without the dimensional stability being affected.The constructional stiffness is increased even further by using astrengthening layer having an elasticity modulus greater than or equalto 50 GPA, in particular greater than or equal to 100 GPA, more inparticular greater than or equal to 150 GPA, more in particular greaterthan or equal to 200 GPA, more in particular greater than or equal to300 GPA, more in particular greater than or equal to 400 GPA.

In a preferred embodiment of a wall panel according to the invention,the wall panel comprises two strengthening layers, which are connectedto a layer of paper/cardboard on either side of the wall panel via anadhesive. Thus a sandwich construction is obtained, in which the wholeof various adhered-together layers of paper/cardboard is connected to aless elastic strengthening layer on both flat outer sides. The result isan even greater constructional stiffness having a correspondingdimensional stability.

It is noted that impregnating the wall panel with, for example, aresinous material not only has the advantage of providing a greaterconstructional stiffness, but also of providing protection againstexternal influences, such as moisture. As a result of said additionalstiffness, fewer layers of corrugated paper/cardboard are in principleneeded in order to give the flat panel the required stiffness. Saidimpregnation preferably takes place by means of vapour deposition,spraying or otherwise, said vapour deposition or spraying taking placein a direction parallel to the direction of the “cell structure” of thecorrugated paper/cardboard that is used. Said impregnation may also beeffected with mechanical means, wherein toothed and/or flat rollers areused for pressing the impregnating medium into the paper/cardboard.

In another preferred embodiment of a wall panel according to theinvention, the strengthening layer is comprised of a fibre material. Inparticular, the fibre material consists of glass fibres, carbon fibres,mineral fibres and/or synthetic fibres. Said synthetic fibres may e.g.be fibres of the type known under the brand names “Kevlar” or “Twaron”.

In another preferred embodiment the strengthening layer comprises alayer of a plastic material. The plastic of said layer of plasticmaterial is preferably selected from the group consisting of PVC-U, PP,PE, ABS, PVC-C and PVDF. It is noted that the above abbreviations relateto the following (plastic) materials.

-   -   PVC-U Polyvinyl chloride (without plasticizer)    -   PP Polypropylene    -   PE Polyethylene    -   ABS Acrylonitrile-Butadiene-Styrene    -   PVC-C Polyvinyl chloride (post-chlorinated)    -   PVDF Polyvinylydene fluoride

In another preferred embodiment of the wall panel according to theinvention, the strengthening layer comprises a layer of rubber. Therubber of said layer of rubber is preferably selected from the groupconsisting of EPDM or NBR. In another preferred variant, thestrengthening layer is made of a metal, in particular stainless steel orwood.

In another preferred embodiment of a wall panel according to theinvention, the wall panel is at least substantially made of an evennumber of layers of paper/cardboard. In combination with thestrengthening layer, this provides a plate-shaped material which ishardly deformable, if at all. Preferably, the wall panel is mirrorsymmetrical with respect to a central longitudinal plane of the wallpanel so as to increase the dimension all stability thereof, so that“warping” is prevented at all times.

The invention also relates to a method for manufacturing a wall panelaccording to the specifications of the invention, wherein the wall panelis at least substantially made of layers of paper/cardboard, each layerat least substantially being made up of a corrugated sublayer and a flatsublayer provided on one side thereof, which layers of paper/cardboardare interconnected via an adhesive applied to the corrugations of thecorrugated sublayers, wherein the wall panel is impregnated, inparticular with a resinous material, and wherein at least onestrengthening layer having a greater elasticity modulus than the layersof paper/cardboard is provided, which strengthening layer is connectedto a layer of paper/cardboard on one side of the wall panel via anadhesive.

It is noted that the term paper is usually used for lighter types ofpaper; in the case of a heavier quality, the term cardboard isfrequently used. Within the framework of the invention, the terms paper,cardboard and weight are not intended to be limitations as regards thetype of material to be used.

The aforesaid resinous material with which the wall panel according tothe invention is impregnated, is preferably an epoxy resin, apolyurethane resin, a polyester resin or a phenol resin. Fire-resistantand/or fire-retarding agents may be added thereto. Preferably, theresinous material with which the wall panel according to the inventionis impregnated also functions as an adhesive for adhering two layers ofpaper/cardboard together, so that a separate adhesive, such as a glue,is not required. To that end, sets consisting of a corrugated sublayerand a flat sublayer provided on one side thereof, which sublayers arealready impregnated with the resinous material, can be placed on top ofeach other so as to be adhered together (after the resinous material hasdried).

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be explained in more detail with reference tofigures illustrating a preferred variant of the invention.

FIG. 1 shows a schematic, perspective view of the present wall panel.

FIG. 2 shows a schematic, detail view of the wall panel in FIG. 1.

FIG. 3 shows a schematic, exploded view of the wall panel in FIG. 1.

DETAILED DESCRIPTION

FIG. 1-3 shows a flat wall panel I according to the invention in theform of a “sandwich”, in the sense that a core 2 built up of severallayers of corrugated cardboard is connected on either side to a lesselastic strengthening layer 3 of a thin material having an elasticitymodulus of about 400 Gpa.

In this case, four layers of corrugated cardboard are provided, whichare each built up of corrugated sublayer 4 and a flat sublayer 5 gluedto one side thereof, using a glue applied to the corrugations 6 of thecorrugated sublayer 4. The core 2 is impregnated with a resinousmaterial. As already said before, the strengthening layers 3 are gluedto both sides of the core 2.

The wall panel 1 is mirror symmetrical with respect to a centrallongitudinal plane 7 of the wall panel 1.

It is noted that the invention is not limited to the embodiment as shownin the figures, but that it also extends to other variants that fallwithin the scope of the appended claims. Thus it will be apparent tothose skilled in the art that the wall panel may exhibit a (slight)curvature, whilst the wall panel may also comprise a curved longitudinaledge.

1. A wall panel comprising: at least one layer including a corrugated sublayer and a flat sub layer wherein flat sublayer is connected with corrugated sublayer; and wherein the corrugated sublayer(s) and the flat sub layer(s) are composed of paper, cardboard or other material containing a high cellulose content; and a strengthening layer adhesively connected to the paper/cardboard layer wherein the wall panel is impregnated with resinous material; and wherein the strengthening layer has a greater elasticity modulus than the paper/cardboard layer.
 2. A wall panel according to claim 1, wherein a second strengthening layer is adhesively connected to the paper/cardboard layer thereby sandwiching the paper/cardboard layer between the two strengthening layers.
 3. A wall panel according to claim 1 wherein the said strengthening layer is made of wood.
 4. A wall panel according to claim 2 wherein the said strengthening layers are made of wood.
 5. A wall panel according to claim 1 wherein the said strengthening layer is made of metal.
 6. A wall panel according to claim 2 wherein the said strengthening layers are made of metal.
 7. A wall panel according to claim 1 wherein the said strengthening layer is made of a fibre material.
 8. A wall panel according to claim 2 wherein the said strengthening layers are made of a fibre material.
 9. A wall panel according to claim 6 wherein the fibre material is selected from the group of glass fibres, carbon fires, mineral fibres, synthetic fibres.
 10. A wall panel according to claim 7 wherein the fibre material is selected from the group of glass fibres, carbon fires, mineral fibres, synthetic fibres.
 11. A wall panel according to claim 1, wherein the said strengthening layer includes a layer of plastic material.
 12. A wall panel according to claim 2, wherein the said strengthening layer includes a layer of plastic material.
 13. A wall panel according to claim 3, wherein the said strengthening layer includes a layer of plastic material.
 14. A wall panel according to claim 4, wherein the said strengthening layer includes a layer of plastic material.
 15. A wall panel according to claim 5, wherein the said strengthening layer includes a layer of plastic material.
 16. A wall panel according to claim 6, wherein the said strengthening layer includes a layer of plastic material.
 17. A wall panel according to claim 7, wherein the said strengthening layer includes a layer of plastic material.
 18. A wall panel according to claim 8, wherein the said strengthening layer includes a layer of plastic material.
 19. A wall panel according to claim 9, wherein the said strengthening layer includes a layer of plastic material.
 20. A wall panel according to claim 1, wherein the said strengthening layer includes a layer of rubber.
 21. A wall panel according to claim 2, wherein the said strengthening layer includes a layer of rubber.
 22. A wall panel according to claim 3, wherein the said strengthening layer includes a layer of rubber.
 23. A wall panel according to claim 4, wherein the said strengthening layer includes a layer of rubber.
 24. A wall panel according to claim 5, wherein the said strengthening layer includes a layer of rubber.
 25. A wall panel according to claim 6, wherein the said strengthening layer includes a layer of rubber.
 26. A wall panel according to claim 7, wherein the said strengthening layer includes a layer of rubber.
 27. A wall panel according to claim 8, wherein the said strengthening layer includes a layer of rubber.
 28. A wall panel according to claim 9, wherein the said strengthening layer includes a layer of rubber.
 29. A wall panel according to claim 10, wherein the said strengthening layer includes a layer of rubber.
 30. A wall panel according to claim 11, wherein the said strengthening layer includes a layer of rubber.
 31. A wall panel according to claim 12, wherein the said strengthening layer includes a layer of rubber.
 32. A wall panel according to claim 13, wherein the said strengthening layer includes a layer of rubber.
 33. A wall panel according to claim 14, wherein the said strengthening layer includes a layer of rubber.
 34. A wall panel according to claim 15, wherein the said strengthening layer includes a layer of rubber.
 35. A wall panel according to claim 16, wherein the said strengthening layer includes a layer of rubber.
 36. A wall panel according to claim 17, wherein the said strengthening layer includes a layer of rubber.
 37. A wall panel according to claim 18, wherein the said strengthening layer includes a layer of rubber.
 38. A wall panel according to claim 19, wherein the said strengthening layer includes a layer of rubber
 39. A wall panel according to claim 2, wherein the wall panel comprises an even number of layers.
 40. A wall panel according to claim 39, wherein the wall panel is mirror symmetrical with respect to a central longitudinal plane of the wall panel.
 41. A method for manufacturing the wall panel comprising: interconnecting layers including a corrugated paper/cardboard sublayer and a flat paper/cardboard sublayer, wherein the layers are interconnected via adhesive applied to the corrugations of the corrugated sublayers, connecting at least one strengthening layer having a greater elasticity modulus than the layers of paper/cardboard is connected to the paper/cardboard layer via an adhesive, wherein the wall is impregnated with a resinous material. 